QUEBEC CITY — A 40th victim of the Lac-Megantic, Que., railway explosion has been identified, but seven others might never be.

The coroner's office said Wednesday that it has identified the remains of Jimmy Sirois, 30, among 47 people who died in a runaway train blast on July 6, 2013.

The office said it is closing its file with seven victims still unidentified.

The coroner and forensic labs in Montreal and the United States worked for nine months to examine remains.

"This work consisted primarily of analyzing fragments and human remains that had been highly altered by the intensity of the fire to which they were exposed, making it impossible to identify all the people who died in the fire," said Genevieve Guilbault, a spokeswoman for the coroner.

The Lac-Megantic disaster is the deadliest railway explosion in Canadian history.